commit 55ef5301fc7f49a2eda5b84b12d816ff051dbfb5
author dougarnett <dougarnett@chromium.org> Mon Jun 12 23:09:40 2017
committer Commit Bot <commit-bot@chromium.org> Mon Jun 12 23:10:05 2017
tree b3f64d558db1ca9166b36b5f15667401137eeeac
parent b815cd6600b8b299285369ae798439c02cfaced9

Adds Lo-Fi fallback support for new Data Reduction Proxy protocol.

Background: the original client-based preview fallback support that
existed in RenderFrameImpl::SendDidCommitProvisionalLoad for main
frame responses was removed in CL 2856223008. This CL now adds fallback
support back in at the same call site but introduces a helper method
to better isolate the (now more complicated) logic with unittests.

This CL also adds integration tests that cover ECT header test coverage requested in bug 691135.

BUG=701802,691135

Review-Url: https://codereview.chromium.org/2910783002
Cr-Commit-Position: refs/heads/master@{#478812}